It has long been known to use a backup pad to support abrasive articles, such as abrasive sheets which may be converted into any form, such as circular discs. The backup pad may be a hand-held pad for manual operation, or a backup pad for use with a power tool such as a rotary or orbital sander. When the backup pad is for use on a rotary power tool, it is necessary to mount the backup pad to the rotary tool in a secure manner to prevent relative rotation between the backup pad and the power tool drive shaft. Typically, the backup pad is bolted to or is threaded engagement with the drive shaft on the power tool. (See for example, U.S. Pat. No. 3,562,968.) Other arrangements for securing the backup pad to the drive shaft of the rotary tool have also been used. (See for example, U.S. Pat. No. 3,270,467.)
However, it is seen that there exists a need for a backup pad that can be mounted securely to a drive shaft so as to prevent relative rotation between the two, and that may be easily released without the use of additional tools.